Detectives were questioning a 35-year-old man today over the murder of teenage model Sally Anne Bowman.
It follows what is understood to be a DNA breakthrough in the case.
The man was held in connection with the 18-year-old's murder at 8.30pm yesterday, reportedly at his workplace in Surrey about 15 miles from the murder scene in Croydon, south London.
Sources described it as a "very significant" development, but police would disclose no further details about the man or the circumstances of his arrest.
He is being held at a police station in south London and officers began questioning him this morning.
The breakthrough was said to have been the result of routine forensic checks to eliminate possible suspects.
Detectives have been carrying out an extensive DNA screening programme in the hunt for Sally Anne's killer.
She was bitten, stabbed and sexually assaulted by a suspected serial sex attacker in Blenheim Crescent, Croydon - just yards from her home - on September 25 last year following a night out.
Earlier this year, officers sent letters to 4,000 men in the local area asking them to provide a voluntary DNA sample to eliminate themselves from the investigation.
Detective Chief Inspector Stuart Cundy said at the time that he believed her murderer had an "incredibly strong local connection" and may live in the area, have family there or work nearby.
In March, detectives set up a DNA screening centre in south Croydon, asking local men who were white or light-skinned and born between 1965 and 1985 to attend.
Sally Anne was attacked after a night out in Croydon, which included a trip to Lloyds Bar before going to a friend's address and heading home.
Neighbours in Croydon heard the blonde teenager screaming in the early hours of Sunday and her body was later found on the pavement next to a skip.
Four men were arrested in September last year in connection with the teenager's murder, one aged 20, another 25 and two aged 26.
All four were released without charge.
Earlier this month, detectives made a fresh appeal on the BBC's Crimewatch programme, based around a new e-fit of a suspect who had been linked by DNA to an indecent assault in July 2001.
The e-fit was compiled by the victim of that attack and released six months on from Sally Anne's death.
Sally Anne, who also worked as a hairdresser, had turned 18 only a week before she died.
She had attended the Brit School for the performing arts in Croydon where former pupils include music stars Morcheeba, Amy Winehouse and Katie Melua, who topped the album charts last year.
But Sally Anne wanted to follow in the footsteps of Croydon-born supermodel Kate Moss and had already begun appearing on the catwalk.Reuse content